Boyd Bolts
Detail from AS12-46-6814,
showing a corner of the top surface of the Central Station with two red-capped Boyd Bolt sleeves on the near edge and an empty socket on the far edge either where a Boyd Bolt popped off when it was released or when the last of the Boyd Bolts holding down the top of the Central Station was released and the top sprang up into its final configuration. Each of the sleeves has a diameter of about 0.75 inches (19 mm) and a height of about 1.5 inches (38 mm).
Various ALSEP experiment modules were attached to the two ALSEP packages with Boyd Bolts. In addition, the top surface of the Central Station was attached to the base by twelve Boyd Bolts, which had to be released before the top could spring up into its final configuration. The bolts were designed by Thomas R. Boyd. US Patent 3368602 ( 0.6 Mb ) , issued to Boyd on 13 February 1968, shows a design that is similar in some ways to the Boyd Bolts flown on Apollo. The bolt described in this patent is threaded into the female portion of the assembly and required approximately ten full turns for release. The design flown on Apollo required only a quarter turn for release. The Apollo design also had a guide sleeve added at the top of the male portion of the assembly to make it easier to get the Universal Handling Tool, used for bolt release, properly aligned while wearing the cumbersome Apollo suit.
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Figures 6 (right) from U.S. Patent 3368602 shows a threaded bolt fully seated in the female portion of the assembly while Figure 5 (right) shows the bolt at the point of release. Presumably, residual compression in the spring at this point will pull the bolt fully free of the female portion of the assembly.
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This 16-mm movie frame shows the Apollo 12 ALSEP Package No. 1 during pre-flight inspection with four red-capped Boyd Bolt sleeves on the near edge securing the top of the Central Station to the bottom. The opening at the top of each sleeve is covered with a thin red-orange foil to help keep dust out.
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Lateral view of a flown Apollo 15 Boyd Bolt sleeve showing the foil cover which was broken by insertion of a UHT into the sleeve. click on the image for a larger version.
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Lateral view of the Boyd Bolt sleeve inverted to show the bottom surface and the opening for the male portion of the assembly. Click on the image for a larger version.
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Close-up of the interior. Click on the image for a larger version.
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Close-up of the foil margin. Click on the image for a larger version.
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Oblique view into the interior of the Rusted Boyd Bolt that Dave Scott found on his desk after returning from the Moon. This view shows us the hexagonal socket into which the tip of the UHT had to be inserted and the central pin that had to be depressed before the socket could be turned.
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Close-up vertical view into the interior of the Rusted Boyd Bolt.
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This frame shows the tip of a Universal Handling Tool (UHT) that has just been removed from the nearby sleeve during the pre-flight inspection of the Apollo 12 ALSEP packages.
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Frame showing Universal Handling Tool fully inserted in the sleeve.
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This detail from Apollo 15 photo AS15-86-11592 shows a Boyd Bolt spring lying on the top of the Central Station.
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This detail from Apollo 12 photo AS12-46-6815 shows the male portion of a Boyd Bolt and the sleeve on top of the Central
Station.
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A second detail from Apollo 15 photo AS15-86-11592 shows the male part of a Boyd Bolt and the sleeve lying on the ground next to the Central Station.
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